KHOA HOC CONG N G H £
AMH HUOIMG CLIA MOIVG DO BRASSIIVOLIDE DEIV B^IMH VAMG LA GAIM XAIMH, IMAIVG SLIAT VA PHAIVI CHAT TRAI BUOI DA XAIMH [Citrus maxiwna [ B u r m . ] Merr.)
TAI HUYEIM KE SACH, Ti[\IH SOC TRAIVG
Lang Hoai Phong^, H u ^ Lfi Anh Nhi^
T r ^ van HSu^ Tr4n Sy Hidu'' T6MTAT
De tai dupe thuc hien nham xac dinh hieu qua cua cac nong do Brassinolide phun qua la len ty le va chi so benh vang la gan xanh, nang suat va p h i n chat buoi Da xanh. Thi nghiem duoc thuc hien tren cay buoi Da xanh 15 nam tuoi tai huy^n Kd Sach. tinh Soc Trang. Thoi gian thitc hien tir thang 6/2017 d^n diang 6/2018. Thi nghipm duQC bo tri theo the thiic khdi ngau nhien hoan toan, sau lan lap iai, mdi lap lai tuong ling voi mOt cay. Nghiem dure la ndng dd Brassinolide (BR): (i) 0,05 nM; (iO 0.10 pM; (iiO 0.15 nM va hai nghiem thuc ddi chung la doi chiing duong phun dung dich ZnSO, 0.5% + MnSO, 0,5% va ddi chimg am phun nuoc. Cac nghi<'m thtrc phun BR dirge phun dinh ky 2 tuan/lan tir khi cay budi chuan bi ra IS den khi thu hoach trai (12 thSng). Su hi^n dien cua vi khuan tanrf/rfa/ws Liberibacter asiaticus trong la truoc va sau thi nghiem dupe xac dinh bang phuong phap PCR vol cap mdi dac lii^u va dinh luong ham luong tinh bot trong \k a giai doan tru6c khi thu hogch. K^t qua cho th^y phun Brassinohde (BR) cr cac nong do 0,10 va 0,15 jiM djnh ky 2 tuan mot Ian co hieu qua len cac chi tieu danh gia b^nh vang la Greening, su hi^n dien cua vi khudn. cai thi^n d^ic tinh ra hoa, nSng suat va pham chat trai buoi Da xanh. Phun BR a nong dp 0,15 pM CO hieu qua lam giam ty 1$ la bi benh, chi so benh va ty le dpt non nhiem benh sau 3 thang xii ly va giam d^n muc th^p nhat sau 12 thang xir ly. Xir ly BR 0.15 pM con lam giam su hien dien ciia vi khuan d^n miic khong phat hien dupe bang ky thuat PCR 6 thoi di^ni 12 thang sau khi xir ly, giam ham lupng tinh b6t ti'ong lii, tang ty le ra hoa dau trai, nang sual va pham chat trai buoi Da xanh.
Tir kh6a.' Brassinolide, dien di D.X.'l Unh bot trong ia. budi Da xanh, vdng la Greening.
I.BATVANBE t*^"^ '^ '•'ly chdng canh {Diaphonna ci'tri) a chau A Su da dang khi hau a cac vung trong trot la dieu ™ ' ^ J n ^ T L^"T "^'"t^ ° ' ' ' * " ™ ' " " " ^ ™ k,(.n ihich hop cho nhieu loai sau benh phat sinh gay '*.• 2""'"; f ' < : ' ' • ™ ''''^ ^enh VL Greening la c6 hai trta cay buoi. la nguyen rf,an anh huong tivc ""^ « ! f ",''*"'' <>=•• " » ^'"° Pl^*' Wen btah o giai bip den nang suit va chat luong Irai ( U Ma, Nhat. ^°?° ^auva thuong hay nham lan vo. bSnh khac nhu 2014). Mot S6 benh dien hinh 6 cay buoi nhu: Benh «"-^"y ^l th.et, kem (Zn) ( U Mai Nhat, 2014).
Tristeza, benh vang la tlioi r^. ghe nham... Trong do Brassinosteroids (BRs) la nhom cac hormone benh vang la Greening CVL Greening) gay hai * ™ "?' co tac dong thiic day su sinh tnrcmg va nghiSm n-ong hen hau hit vuon cay buoi. Benh do 3 l<hang benh o cay trong (NguySn Minh Chon, 2010).
dong vi khuan Liberibacter gay ra la Caiididatus ^ ^ ^^ ''en quan den nhieu qua Uinh phat hien cua Liberibacter asiaticus (Las), ranrf/rfa&s Liberibacter * ^ ^ ^4'-W vu(m dai, su mo rong la, su nay mam cua afilcanus va Candidatus Liberibacter americanus ^at, sura hoa va lao hoa (Rao va rtv, 2002). Ket qua (Canales va ctv.. 2016). Cac dong vi khuan nay song nghien ciiu v4 dieu tri benh VL Greening VOT BRs cua trong mach libe ciia cay va lay tiTiyen tii cay nay sang Canales va ctv. (2016) cho thay ap dung cay khac thong qua cac mat ghep va moi gioi truyen Epibrassinolide (EBR) lam giam dang ke tac nhan
gay benh VL Greening tren cay co mui. cay bi binh phuc roi rat toi va phat trien bmh thuong. D6ng thoi, ' H(.c "C-n cao hoc njanh Kho;. llQC cav udng. Truimg Dai f f "*. ™" l^'* *ich mot sd gen phong ve vffl vi h9c An Giang "*"=" La' ™a cay buoi (Canales va etv.. 2016). Do
" Bo mon Khoa hoc cay uong. Khoa Nong nghiep. Truong vay, nghien ciiu nay duoc thuc hien nham danh '' Dai hoc can Tho hieu qua cua nong do Brassinohde phun qua H \,.ft Email: [email protected] vn "-n ty .U NONG NGHIEP VA PHAT TRIEN NONG THON - KY 1 - THANG 9/20,9
KHOA HOC CONG N G H l
It va chi sd b^nh vang la gan xanh, nang suJit va pham chat buoi Da xanh.
2 . VAT L t U VA PHUDNB PHAP THI NGHEM
Thi nghidm dupe thuc hi^n tai vuim buoi Da xanh 15 n3m tuoi tir thang 6/2017 den 6/2018 tai huy^n K^ Sach, tinh Soc TrSng. Cac nghiem thirc phun Brassinolide (BR) duoc phun dmh ky 2 tuin mpt ldn bat dau tir thang 6/2017. BR ducrc sir diing la dang ch^ pham thuong mai Nyro O.OISL (Brassinohde: 0,01% w/w) cua Cong ty TNHH TM &
SX Ng(?c Yein. Cay buoi Da xanh 15 nam tuoi duac nhan gi6ng bang phuong phap chiet, cay bum duac trong tr&n n^n dat phii sa co len liep, co muong tuoi ti^u, thoat nuoc t6t. khoang each trong (cay x cay x h ^ g ) : 3 X 3 X 4 m. Cay dugc chgn co thai gian sinh truong, ty 1? b^nh va cap b§nh tuang duong nhau.
Tinh tr^ng benh ciia cay truoc khi thi nghiem dupe xie nhan bang phan ling PCR vai cap moi dac hieu (Forward primer Oil: 5' CAC CGA AGA TAT GGA CAA CA 3' va Reverse primer 0I2c: 5' GAG GTT CTG GTG GTT 111 CTG 3') cua Jagouex ra ctv.
(1996).
Thi nghiem dup^ bd tri theo the thuc khdi ngku nhi^n hoan toan, co 5 nghiem thuc trong do 3 nghi?ni thtrc la nong dp BR phun qua la: (0,05 pM, 0,10 \M, 0,15 pM) va hai nghiem thuc ddi chimg la ddi chiing duong phun hdn hop ZnS04 0,5% + MnSOj 0,5% a dgng EDTA dua tren nghien ciiu ciia Nguyin Thi Minh Chau va Nguyin Bao Ve (2005) va ddi chiing am phun nude. M6i nghiem thirc cd 6 Ian lap l^i, mdi lan lap Iai tuong img vdi mdt cay. Tat ca cac nghiem thuc duoc phun dinh ky 2 tudn/lan, trong 12 thang.
Cac chi Ueu sinh trudng cua cay dugc theo doi trong 12 thang, dinh ky 1 thang/lan bat dau tir khi bo tri thi nghidm cho ddn khi thu hoach ti'ai, tong cdng 12 lan. Cac chi tieu quan sat bao gom: chu vi gdc (cm) do d vi tri gdc lon nhat tren mat dat; chu vi than cay (cm): do a vi tri than ldn nhat; chilu cao cay (cm): do tir mat dat den dinh chdi cao nhat ciia cay:
chi^u rpng tan cay (cm): do tir hai chdp la rpng nhat cua cay.
Ty 1^ benh va cap benh dugc danh gia theo QCVN 01 - 119:2012/BNN-FTNT. Quy chuan ky thuat Qudc gia ve phuong phap difiu tra phat hien sinh vat gay hai tren cay an trai cd miii. Tren mdi cay 5 canh chinh cd ty le benh va cap benh VL Greening tirong duong nhau dugc danh dau va danh gia ty le {%) la tren canh bi nhidm benh va "phan cap benh
nhu sau: Mdi cay chon va danh dau 5 canh chinh cd t\' le benh va csip benh VL Greening tuang dirong nhau, dieu tra ty le (%) la tren canh danh dau bj nhi^m benh va phan cap benh (Cap 1: 1-10%: cap 3:
>10-20%; cap 5: >2a40%; cjip 7: >40^0%: cap 9: >80% ty le dien tich la bi hai tren canh cay), tir do tinh chi sd benh (CSB) - Disease index (%) bang cdng thtic:
CSB {%) - {[(N, X 1) +...+ (N, x n)]/ (N x K)} x 100.
trong dd: N,: la sd la dieu tra bi hai d cap 1; N^: \i sd la dieu tra bi hai d- cap n; N: la tong la dilu tra; K: la cap hai cao nhat cua thang phan cip (cap 9)". tir dd tinh chi s6 benh.
Cac chi tieu nang suat va thanh phan nang suat diroc thu thap bang each can va ddm tdng sd trai/cay; pham chat trai bao gdm acid tdng sd, dg Brix, ham lirong vitamin C, ham lirong ntrde trong thit trai dugc ghi nhan bang each phan tich 5 trai/cay. Ham lupng acid tdng sd trong trai dupe phan tich dua theo qui trinh ciia TCVN 5483-1991.
Ham lugng vitamin C duge phan tieh theo phirong phap chuan dp vdi dung dich 2,6 dichlorophenolindophenol (TCVN 6427-2:1998). Tinh trang benh ciia cay trudc va sau thi nghidm duge xac dinh dua tren phan ung PCR thuc hi§n trfin 10 la thu xung quanh tan tren mdi cay. Qui trinh phan img PCR dupe thuc hien theo mo ta cua Hung va ctv.
(1999). Ngoai ra, ham lupng tinh bdt trong la cung duge xac dinh de danh gia tinh trang benh VL Greening do cay cd mui nhiim benh VL Greening cd su tich luy tinh bpt trong la cao. Dinh lupng tinh bdt trong la dugc thuc hien dua tren phan img led - tinh bpt theo quy trinh eua Whitaker va ctv. (2014).
Phan mem Genstat dugc diing de phan tich phuong sai cd hieu ehinh cho lay mau lap lai (repeated measure ANOVA) va so sanh sir khac bigt giua cac nghiem thtrc bang phep kiem dinh LSD d miic y nghia 5%.
Hinh 1. C^y budi Da xanh 15 nam tudi dimg Um v|t lidu thi nghidm. Cay bi b§nh vang 1^ Greening (cdi cpc, vang la), ]A nhd hon binh thuimg {tai thd)
3. KET QUA VA THAO LUAN r».XTTmcM MONG THON - KY 1 -THANG 9/2019
KHOA HOC CONG NGHt 3.1. Tmh hinh sinh truong cua c4y buoi Da xanh
trong thi n g h i ^
Qua ket qua phan tich thong ke (Bang 1) cho thay chu vi gdc. chu vi than, chieu cao cay, chieu rpng tan cay buoi Da xanh dirpc do hiroc khi thi nghitm khac biet khong co y nghia fliong ke. Bieu nay cho thay cay buoi Da xanh duoc dimg trong thi nghidm CO dp dong deu nhau.
BSng 1. D$c tinh ndng hpc cSy btioi Da xanh tnr6c khi thi n g h i ^ tji h u y ^ K^ S4ch.
tinh S6c Trang, 2018
3.2. l y If benh, chi s6 b«nh vtog 14 Greening 3.2.1. Didn bidn tyle la binh tr^n canli ciiy Qua k a qua dt bang 2 cho thay o thai diem t u o c khi phun BR chi so benh giiia cac nghiem thiic kh^c biet khong y nghia qua phan tich thdng ke, dieu nay cho thay cac cay buoi Da xanh duoc chpn lain vgt lieu thi nghiSm co chi s6 bSnh dong deu nhau. Ddi vol diin bien frung binh ty 1? la b^nh trSn canh qua cac thang, nhin chung giam deu va cd y nghia bat dju til thang thii 4 sau khi xu ly (SKXL) (42,5%). 0 thdi diem thang thu 6 sau khi xti ly trung binh ty Ip la benh giam cd y nghia so vdi 2 thang tnrdc (40*). Tit thang thii 7 den thang thii 12 SKXL dung binh ty le la bpnh giam chi cdn 25,9%, Sau khi xu ly BR trung bmh ty Id la benh tren canh giam 56% sau 12 thang xu ly. Theo Khripach va ctv (2003), Brassinohde la mpt lactone steroid hr nhien thupc nhdm chat BRs, cd kha nang giup cay trdng tang tinh chdng chiu cac lac nhan sinh hpc nhu sau bdnh va phi sinh hpc nhu dieu kipn mdi trudng bat loi. Bdn canh dd, day la hoat chat cd nguon gdc hr nhidn dupe chiet tii thuc vat va dupe su dung vdi lidu lupng thap, an tpan vdi mdi Unidng va khdng luu tdn du lupng ddc td trdn
„,.. ,. . 11 .i !.•.=,;(.- A • 1,1., th^r,,. ndng san (Nguyen Minh Chon, 2005).
Ghi chu: ns: khdc bi$t lihong co y nghia Ihong & v s J ki miic y nghia 596. SR: Brassinolide: DC duong:
phun ZnSOj * MnSO, 0.5%: DC am: Phun nuoc.
BSng 2. T}' le (%) l i benh vang l i Greening trdn canh b cic thdi di^m quan sit dudi sir anh hudng ctia cic ndng do Brassinolide khAc nhau tjil huyen Kd Sich, tinh Sdc Trang, 2018
Nghiem thlic BR 0,05 pM BR 0,10 pM BR 0,15 pM DC duong DC am F LSD CV(%)
Chu vi gdc (cm) 40,7 40,7 40,3 40,3 40,2 ns 1,12
2,3 Chu
vi than (cm) 37.5 37,7 37,5 37,5 37,7 ns 0,80
1,8 Chieu
cao cay (cm) 251,0 250,3 250,8 250,2 250,5 ns 0,84
0,3 Chieu
rdng tan (cm) 322,5 321,3 321,8 322,8 323,5 ns 3,19
0.8
Nghidm thlic BR 0,05 pM BR 0,10 pM BR 0,15 pM DC duong DC am Trung hinh F (Ngliiem thlic F CThdi diem qua F (NT*TDQS)=*
Thdi diem quan sat (thimg sau khi xii ly) TKXL
46,8 46,2 46,9 45,3 46.6 46,3"
1 54,1 45,2 47,2 48,5 48,9 48,8*
2 51,0 43,9 39,6 45,7 48,1 45,7»
3 47,5 41,7 37,6 47.7 74,2 49,V*
4 40,2 34.9 28,9 38,9 69,8 42,5^
5 39,0 34,6 22,5 40,1 74,7 42,2^
6 33,8 35,6 15,6 43,1 72,0 40,0"
7 36,9 29,1 11,8 37,7 72,0 37,5'-
8 32,4 26,8 7,0 33,0 72,2 34,3f
9 38,8 21,6 3,7 32,2 71,0 33,4™
10 38,5 17,7 2,4 28,3 71,4 31,7''
11 39,6 11,7 1,5 25,4 71,4 27,9"
NT)-**,LSD„„-2,04 in sat-TDQS)=**, LSD„„-2,21
*, LSD„„-5,22
12 36,6 11,2 1,4 20,1 70,2 25,9"
CV (%) - 10,0
Ghi chu: Trong cung mot eft hoac hang, cac sd co chu dieo sau gidng nhau dii kliac biet khong cd y nghia tiidng ke theo phep tiid LSD 5%: ' *:khac biet co y nghia tiidng ke IX. BP: Brassinolide: DC: Ddi chung;
DC duong pliun ZnSO, + MnSO, 0,5%: DC am: Phun nude: TB: Tmng binh: TKXL Uudc khi xd ly.
Xu ly BR vdi ndng dd 0,15 pM ty Ip bpnh giam dan tir 46,9% (TKXL) xudng miic 1,4% d thdi diem 12 thang SKXL, thip nhat frong cac nghiem thiic khao sal, Dieu nay cho thay ty- le la benh VL Greenmg fren canh cay budi Da xanh dupe xii ly vdi BR hai ndng
do 0,10 va 0,15 pM giam din theo thdi gian xii ly va hidu qua tang len ciing vdi su gia lang ndng do BR.
Canales va ctv. (2016) khang dinh rang mat so vi khuan gay bdnh VL Greening cay co mui gan, dang ke khi xu ly Epibrassinolide (EBR) sau 3 thang Sau 36 NONG NGHIEP VA PHAT TRIEN NONG THON - KY 1 - THANG 9/2019
KHOA HOC CONG NGHE
khi xir ly EBR. cac gen phdng thu deu cd muc bieu hi?n cao rd r?t va dupe duy tri a tat ca cac thdi diem khao sat tir do lam giam benh theo thdi gian. duy tri dn dinh va giup cay phuc hdi sau khi nhi§m benh VL Greening (Canales va ctv., 2016).
3.2.2. Diin bien chi sd bdnh (%) tren canh cay Chi sd benh trung binh khac biet cd y nghia thdng ke giira cac nghiem thiic phun BR d cac ndng dp, nghidm thuc ddi chung duong va nghiem thiic ddi chiing am d' muc y nghia 1% (Bang 3). Chi sd b^nh trung binh cd xu the giam dan cd y nghia bat dau tir thang thii 3 SKXL (57,3%). O thdi diem thang
(39,3%) va den thang thir 12 SKXL chi cdn (27.6%).
Chi sd benh VL Greening d nghidm thiic xii ly BR 0,15 pM da giam 70% sau 4 thang xii ly va den thang thii 12 thi chi sd benh chi cdn 1,9%. Dieu nay cho thay phun BR nong dd 0,15 pM cd hieu qua lam giam chi sd benh rait ro sau 12 thang xu ly. Ket qua nay phii hpp vdi nghien ciiu cua Canales va ctv. (2016) khang dinh ring mat sd vi khuan gay benh VL Greening cay cd mui giam ro ret khi xii ly vdi EBR sau 3 thang xii ly. Chinh vi vay, khi phun BR tren cay budi da xanh nhiem \ T Greening lam giam chi sd benh ro ret
thti 4 SKXL trung binh chi sd benh giam ro ret
B5ng 3. Chi sd b§nh - Disease index 00 ghi nhan trdn cSy budi Da xanh b cac thdi di^m quan sAt t^i h u y ^ K^ sach, tinh Sdc Tr^ng. 2018
Nghiem thuc BR 0.05 pM BR 0,10 pM BR 0,15 pM DC duong D C i n i Trung binh
Thoi diem quan sat (thang sau khi xii lv) TKXL
63,0 68,2 65,9 65,9 65,9 65,8"'
1 65,2 60,7 63,0 63,0 65,9 63,6"'
2 70,4 71,1 59,3 65,9 71,9 67,7"
3 48.2 57,8 55,6 53,3 71,9 57.3'~
4 29,3 40,0 15,2 39,3 72,6 39,3"
5 17,8 27,4 12,2 22,2 73,3 30.6'f
6 18,5 20,7 7.8 22,2 80,0 29,9':'
7 28,2 18,5 5,9 21,1 83.0 Z\.?,'^
8 28,2 15,6 5,9 20,0 83.0 30,5"
9 23,7 14,1 3,3 17,8 83,0 28,4""
10 2,'i,9 9,3 2,6 16,3 83,7 27,6'
11 2,5,2
8,9 4,4 12,6 91,1 28,4''
12 25,9
8,5 1,9 10,7 91,1 27,6' F (Nghiem thlic - N T ) - " , LSD„,„. 2,17
F CThfli diem quan sat-TDQS)-**, LSD„,„-3,44 F ( N T T B Q S ) . * * , LSD„,„.7,77
CV (%) . 14,3
Ghi chii: Trong cung mdt cdt hoac hang, cac sd cd chd Uieo sau gidng nhau tiii khac biet khong cd y nghia thdng kd theo phep thd LSD 5%; **: khac bidt cd y nghia thdng kd 1%. BR: Brassinolide; DC duong:
phun ZnSO.,+MnSO., 0,5%; DC am: Phun nude: TB: Tivng binh; TKXL tnrdc khi xuly.
3.3. 1 ^ 16 dpt non bi nhi6m bdnh v ^ g la Greening {%)
B ^ 4. If 1§ (%) b^nh v ^ g \k Greening tren dpt non buoi Da xanh a cic thdi di6m quan sat dudi su anh hudng cua c ^ ndng dp Brassinolide tai h u y ^ Ke Sach, tinh Sdc TrSng, 2018
BR 0,05 p M BR 0,10 p M BR 0,15 p M D C dirong DC am T m n g b i n h
T h d i d i e m q u a n sat (than^
1 9,3 7,6 2,8 8,5 39,5 13,5'=
2 16,7 10,8 3,4 15,0 86,0 26,4*
3 26,2 15,7 3,9 15,4 76,5 27,5*
4 15,6
7,4 1,9 10,0 74,6 21,9=
5 18,3 8,2 0,8 10,4 44,9 16,5°'!
6 9,9 9,9 0,6 10,4 61,1 1 8 , 4 "
s a u k h 7 11,3
9,8 0,5 9,2 76,0 21,4'*"
xirly) 8 17.9
9,8 0,5 10,1 67,0 21,1"^
9 17,4 10,6 0,4 10,4 71,5 22,0"
10 16,0
8,4 0,0 11,4 64,7 2 0 , 1 " ' F ( N g h i e m thiic - N T ) - * * , LSD„m - 1,54
F (Thdi d i e m q u a n s a t - T D Q S ) = " , LSD„„5-2,99 F ( N T * T D Q S ) . * * , LSD„„5=6,56
CV (%) = 6,2
Ghi chu: Trong cung mot cot hoac hang, cac sd co chir tiieo sau giong nhau thi khdc biet khong co y nghia tiidng ke tiieo phep did LSD 5%: ": kliac biet co y nghia thdng ke 1%. BR: Brassinolide: DC dutmg:
phun ZnSO, + MnSO, 0,5%: BC am: Phun nude: TB: Tmng bmh.
BUAT TDicM MONG THON - KY 1 - THANG 9/2019 37
KHOA HOC C 6 N 0 N G H t
Ket qua d bang 4 cho thay tai cac thdi diem quan sat i\' le dpt non bi nhilm benh VL Greening trung binh cua cac nghiem thiic phun BR va ddi chung duong khac biet co y nghia thong ke so voi nghiem thlic ddi chiing am vao cac thdi diem quan sat NHhuiii thlic phun BR ndng dd 0,15 iiM cd ty le dot non nhiem benh giam ro rdt va cd y nghia d thai didm 4 thang SKXL (1,9%). 6 thoi diem thang thtf 5 SKXL ty le dpi non giam xudng (0.8%), giam 42% so vdi (hang tnrdc, sau 12 thang ty 1? benh tren dpt non gan nhu khong cd (0,0%). Kt-t qua cho thay phun BR lam cay bum Da xanh hi nhiem benh M. Greening phuc hdi, nhung dgt non tren canh cay hi nhiem b^nh VI. Greening sinh tnrdng, phat tridn tdt va ty le nhidm b^nh rat thap.
3.4. C h ^ doan b^nh vdng IA Greening 3.-1.1. Chan doan b^ig phuong phap PCR Phan irng FCR sir dung cap mdi chuyen bi^t, vdi san ph^m khuech dai cd kich thudc 226 bp, duoc diing dd chan doan su hi?n dipn ciia vi khuan gay benh VL Greening. Qua kdt qua phd dien di DXA d hinh 2A (0.05 pM). 2B (0,10 pM) va 2D (doi chiing duong) cho Ihay tat ca 12 gieng deu duong tinh vdi vi khuan gay bpnh VL Greening, dieu do cho thay mau
226 b p
la budi Da xanh tnroc va sau thi nghidm ddu nhiem benh. Nhu v^y, cac nghiem thiic phun BR ndng dd 0,05 pM va 0,10 pM va nghiem thuc doi chmig duong tren budi Da xanh deu khdng lam hgn che benh VL Greening. Rieng nghiem thuc ddi chiing am tlid hien benh VL Greening tnroc va sau thi nghiem ro nhat (Hinh 2E). Tuy nhien ddi vdi nghidm thuc phun BR nong dp 0,15 pM trudc thi nghiem cho kdt qua duong tinh vdi benh, nhung sau thi nghiem cho kdt qua am tinh vdi bdnh (Hinh 2C). Ket qua nay cho thay khi phun qua la vdi BR ndng dp 0,15 pM sau 12 thang giiip cay budi Da xanh nhidm bdnh VL Greening phuc hdi va giam benh ro rdt Didu nay phii hpp vdi nhan dinh cua Canales va ctv. (2016) cho rang mat dp vi khuan gay benh VL Greening tren cay cd mui giam dang ke hau nhu bang khdng sau 12 thang dieu tri vdi EBR Khi xii ly EBR cd tac dung kich thich cac gen phdng thii vdi vi khuan gay bpnh
\T_ Greening ngan can sir xam nhap va bidu hidn cua vi khuan nay, chinh vi the cay budi Da xanh bi nhidm benh VL Greening dupe xir ly vdi BR sau 12 diang cbo ket qua am tinh khi chan doan bang ky thuSt PCR vdi cap mdi dac hidu.
226 bp-
;26 bp->-
Hinh 2. Phd di^n di DNA trong la budi Da xanh truijc vA sau khi xir 1^ 6 cac ndng dd Brassinohde (BR) khd nhau. A) nghidm thiic phun BR 0,05 pM; B) nghidm thiic phun BR 0,10 pM; Q nghidm thiic phun BR 0 15^^
pM; D) ddi chiing duong; E) ddi chiing am ' Ghi chd- Trong tat ca hinli A B. C. D, E: Gieng .M. thang DNA chuan 1 kb; Gidng "+": ddi chun
duong tmh: Gieng tu IS: miu la budi Da xanh truoc tin ngliiem; Gieng lu 7-12: mau la buui Da xanl • T - nghiem.
N O N G NGHIEP VA PHAT TRIEN N O N G THON - KY 1 - THANG 9/2019
KHOA HOC CdNG NGHl
3.4.2. Dinh lugng tinh bdt tiong la
Ham lupng tinh bdt trong la budi Da xanh giira cac nghidm thiic phun BR va ddi chimg khac biet cd y nghia thdng k6 (Hinh 3). Ham lupng tinh hot thap nhat d nghidm thiic phun BR 0,15 pM (0.74 m g / g mau la), thap nhat d nghiem thiic ddi chiing am va phun BR 0.05 pM didu nay cho thay phun BR d- ndng dd thap khdng lam giam ham lupng tinh bdt trong la.
Schneider (1968) cho rang tinh bpt trong la cay cd mui tich luy bat thudng trong khi cay bi nhilm bdnh VL Greening. Ket qua phan tich dinh lupng tinh bdt trung binh cua ba gidng cam quyt {Citrus depressa.
Citrus reticulata, Citrus oto) cho thay ham lupng tinh bpt trong la bi nhidm VL greening cao hon so vdi trong la khde manh (Takushi va ctv., 2007). Do dd, djnh lupng ham lupng tinh bpt trong la la mdt chi tifiu quan trpng dd chan doan miic dp nhidm bdnh VL Greening trgn cay cd mui, sau khi xtr ly BR d nong dp 0,15 pM ham lupng tinh bpt giam xudng ro r^t cho thay cay budi Da xanh bi nhi^m b?nh VL Greening da phuc hdi tdt.
Hinh 3. Ham lupng tinh bdt trong ]A budi Da xanh dudi svr anh hudng cua cdc ndng dd Brassinolide khdc nhau t ^ huydn Kd Sach,
tinh Sdc Trang, 2018 3.5. Sv ra hoa, d^u trii
Qua kdt qua a bang 5 cho thay ty le ra hoa a cac nghidm thuc phun BR va ddi chiing duong khac biet CO y nghia qua phan tich thdng ke a muc y nghia 1%
so vdi nghiem thiic do'i chiing am. Trong dd, ty le ra hoa cao nhat a nghiem thuc phun BR ndng do 0,15 pM la 60,5%, tlia'p nhat d- nghiem thiic ddi chung am ia 29,2%. Ty Id ra hoa tren cay budi Da xanh dupe xii ly vdi BR cd xu hudng tang dan vdi su gia tang ndng ddBR.
Ty le dau trai giua cac nghiem thiic cd phun BR va ddi chiing duong khac biet cd y nghia thdng ke a
muc y nghia 1% so vdi ddi chiing am (Bang 5). Nhin chung, tat ca cac nghiem thirc cd phun BR d^u lam tang ^ le dau trai tren cay budi Da xanh.
Bang 5. Ty 1§ ra hoa vd ty Id d&u tidi trdn cdy budi Da xanh dudi su dnh hudng cua cdc ndng dd Brassinolide khac nhau t ^ huy^n K^ Sdch,
tinh Sdc Trdng. 2018 Ndng dp
Brassinolide BR 0,05 pM BR 0,10 uM BR 0,15 pM DC duong DC dm Trung binh F CV(%)
Ty le ra hoa
(%)
30,4""
42,7^
60,5"
35,8' 29,2'' 39,7
*•
13,46
Ty le dau h-ai(%)
47,5' 64,2' 61,6' 58,5"
48,3' 56,0
•*
9,71 Ghi chd- Trong ciing mdt cot, cac sd cd chti- theo sau gidng nhau thi khdng khac bidt cd y nghia thdng ke theo pbep tbir LSD 5%. * *: khac biet co y ngbia thdng ke 1%. BR: Brassinolide; DC duong: phun ZnSOj ^ MnSO., 0.5%; DC am: Phun nude.
3.6. Ndng su^t vd y^u td cdu thdnh ndng sudt Tdng sd trai/cdy a cdc nghifm thiic cd phun BR d cac ndng dp khac nhau so vdi ddi chiing khac bidt cd y nghia qua phan tich thdng ke b muc y' nghia 1%, trong dd nghiem thiic phun BR nong dp 0,15 pM cd sd trai/cay cao nhat (27,3 Irai/cay) thap nhat d nghiem thirc ddi chimg am (12,5 trai/cay) (Bang 6).
Qua ket qua d bang 6 cho thay khdi lupng trai giira cac nghiem thuc phun BR b cac ndng dp khdc nhau so vdi ddi chiing khac biet co y nghia qua phan tich thdng ke d miic y nghia 1%. Trong dd, khdi lupng trai d' nghiem thiic phun BR 0,15 pM la cao nhat (1.046,2 g), thap nhat la nghidm thiic ddi chimg am (431,4 g).
Nang suat trai dupe quyet dinh bdi sd trai va khoi lupng trai. Kdt qua thdng ke (Bang 6) cho thay nang suat trdi giua cac nghiem thirc phun BR so vdi ddi chiing khac biet cd y nghia thdng ke (miic y nghia 1%). Nghiem thiic cd nang suat cao nhat la nghiem thuc phun BR 0,15 pM (28,6 kg/cdy), khdc biet cd y nghia thdng ke so vdi cac nghiem thuc cdn lai. thap nhat la nghiem thuc ddi chimg am (5,4 kg/cay). Dieu nay phit hpp voi nhan dinh ciia Wang va ctv. (2004) cho rdng khdi luong ti-ai cam tdng khi
JI OMAT wim NONG THON - KY 1 - THANG 9/2019
KHOA HOC CONG NGHi xu ly VOI BR. Ket qua ndy cho thay viec phun BR xu
ly bpnh VL Greening ddng thdi cung lam tang ndng suat tren cdy budi Da xanh. Didu nay phii hpp vdi ghi nhdn tir nghien cuu cua Vardhini »i Rao (1998).
Krishna (2003) v^ vai tro giup gia tdng nang suat cay trdng aja Brassinosteroids.
Bdng 6. Sd trdi/cdy, khdi lupng trdi vd ndng sudt trdi tren cdy budi Da Xanh dudi dnh hudng ciia cdc ndng dp Brassinolide khdc nhau tai huy$n Kd Sdch,
tinh Sdc Traog, 2018 Nghiem thuc
m 0,05 pM
So Khoi lirong trai/cay , trai (g)
Nang , (kg/cay) 1-1.3' 925.4' BR 0,10 iiM
BRO.l.'yiM DC (luimfi DC iim Trung binh F CV(%)
19.7'' 27.3- 20,2' 12,.5' 18.8 6,59
•*
uiKi.j;:!^
1.046.2"
9.H4.1'' 431.4'' 879.i;
19.9'' 28,6"
19,9' 5,4'' 17.4
! ••
3,54 8,18 Gbi elm: "• kliac biet cd y ngbia thdng ke IX. Trong Cling mdt cpt. cac sd cd chu theo sau gidng nbau tiu khdng khac biet cd y ngbia tiidng kd tiieo pbep tiid LSD 5%. BR- Brassinolide; DC duong: phun ZnSO4 + MnSO^
0,5%: DC am: Phun nude.
3.7. Phdm chdt trdi
Qua ket qua thdng ke d bang 7 cho thay dd Bnx cua trdi budi Da xanh d' cdc nghiem thirc phun BR vd ddi chimg duong khdc bi?t cd y nghia thdng ke voi ddi chiing am miic y nghia 1%. Nghidm thuc phun BR 0,15 pM cd dp Brix cao nhat (10,9%) khdc biet cd y nghia thdng ke so vdi nghiem thuc doi chung dirong vd 2 nghidm thirc phun BR cdn lgi, thdp nhdt a nghidm thiic ddi chiing dm (7,3%). Do dd, phun BR iidng dd 0,15 pM cd y nghia lam tang dd Brix cua cdy boi Da xanh, BR khong nhtmg giup gidm trieu chung benh VL Greening 0 cay budi Da xanh ma cdn giiip tang dd Brix la mdt chi tieu quan trpng trong viec quyet dinh pham chat trdi budi. Theo Nguyin Bao
\'i' va Le Thanh Phong, (2011) budi Da xanh cd dp Brix 9.5 -12%.
Ham luong axit tdng sd trong trdi budi Da xanh giira cac nghiem thuc co phun BR a cdc ndng dd khac nhau va ddi chung durnig khac biet co y nghia thong ke mirc y nghia 5% so voi nghiem thiic ddi
chung dm. Nghidm thiic co hdm lupng axit long sd cao nhdt la phun BR 0.15 pM (0,22 g/L) v;i thdp nhdt o nghidm thirc ddi chimg dm (0,04 g/L) (Bang *")•
Ham luong nuoc va hdm lupng vitamin C trong dich trai budi Da xanh giua cdc nghidm thuc cd phun BR d va ddi chimg duong khac bi^t cd y nghia thdng ke miic y nghia 1% so vdi nghidm thiic ddi chiing am (Bang 7). Nghiem thiic ddi chiing duong va cdc nghiem thuc cd xu ly BR deu cd ham lupng nude vd ham lupng vitamin C trong thit trdi cao hon so vdi ddi chiing khong xii ly.
Tdm lai, cdc nghiem thuc xii ly BR giiip khdc phuc hien tupng trai bi xa vd tdng ham lupng acid tdng sd, hdm lupng nude trong thit trai va ham lupng vitamin C cung gia tdng so vdi doi chiing dm, didu nay cbo thay cay budi Da xanh bi bdnh VL Greening dd duoc phuc hdi sau khi phun qua la vdi BR d' ndng dp 0,15 pM,
Bang 7. Hdm lupng nude, dO Brix, axit tdng sd, vitamin C trong trdi budi Da xanh dudi su anh hudng
ciia cdc ndng dp BR khdc nhau t?ii huyfin K^ Sdch,
Nghidm thu^;
0,05 uM 0,10 tiM 0,15 nM DC duong DC am Trung binh F CV(%)
tinhS Dp Brix
(%)
8,4"
9,3' 10,9' 10,3' 7,3' 9,3 3,91
**
6c Tran TA (g/L) 0,09' 0,10' 0,22- 0,10' 0,04' 0,11 9,09
*
g, 2018 Ham lugng nuw: (%)
67,3"
71,4"
73,9"
70,2"
48,8' 66,3
.»
7,74 Vitamin
C (mg/100
gmSu uot) 27,9' 31,1' 40,3"
39,5"
18,9' 31,5
»,
13,2 Ghi chu: ', '•: kliac biet co y nghia tiidng ke 5%
va IX. Trong ciing mot cpt cac sd co chu tiieo sau giong nhau tiii khong khac biet co y nghia tiidng ki tiieo phep thd LSD 5% BR: Brassinolide: DC duong:
phun ZnSO, + MnSO, 0,5%: DC am: Phun nuoc.
4.KETLUANVHBE)ai)iT 4.1.KStluan
Phun BR qua la 2 tuSn mpt Ian 6 cac nong dp khac nhau l,6n tuc trpng 12 thang co hieu q„a doi v™
benh VL Greening, ty 1^ benh va chi si, benh luam dan ke tu thoi diem 1 thang sau khi xii ly va dat h
NONG NGHIEP VA PHAT TRIEN NONG THON - KY 1 - THANG 9/20,9
KHOA HOC CONG NGHE
qua cao nhat ldn su sinh trudng, nang sudt va pham chat trai budi Da xanh d thdi diem 12 thang sau khi xirly.
Phun BR qua la d ndng dp 0,15 pM ti'en budi Da xanh dinh ki 2 tuan/lan lien tuc tir khi cdy chuan bi ra la cho ddn khi thu hoach cd hieu qua lam giam ty 1$ bdnh. chi sd benh va ty Id benh ciia Id non mdi xuat hidn gan nhu khdng dang ke. tang ty le ra hoa va ddu trdi cao (60,5 va 61,6%). sd trdi/cay, khdi lupng trdi vd nang suat (27,3 trdi, 1046,2 g vd 28.6 kg/cdy). Phun BR ndng dd 0,15 pM ciing 1dm tang ham lupng nude trong thit trdi, dp Brix vd ham lupng vitamin C, nang cao pham chat trdi budi Da xanh.
Ngoai ra. kdt qua didn di DNA ddi vdi cay budi Da xanh bi nhidm benh VL Greening thdi diem 12 thdng sau phun BR ndng dp 0,15 pM cho kdt qua dm tinh, ham lupng tinh bdt tich luy trong la thap nhdt (0,74 mg/g Id) so vdi cdc nghidm thiic cdn lai.
4.2. D 6 xu^t
Cd the dp dung phun BR ndng dp 0,15 pM dinh ky 2 tudn mpt lan de Idm giam cdc tri&u chung benh vdng Id Greening, tdng nang suat va pham chdt trai budi Da xanh.
Can tidp tuc nghien ciiu hieu qud cda BR len bdnh vang la Greening tren cay budi Da xanh vd cdc gidng budi khac de cd ket luan chdc chan ban.
TA] UEU THAM KHAO
1. Canales, E., Coll, Y., Herndndez, I., Portieles, R., Garcia, M. R., Ldpez. Y., ... Hidalgo, 0 . B. (2016).
CandidatusLiheribacter asiaticus. Causal agent of citrus huanglongbing. is reduced by treatment with brassinosteroids. FLOS ONE. 2012,185,118 -130.
2. Hung. T. H., Wu, H. L & Su, H. J. (1999).
Development of a rapid method for the diagnosis of citrus greening disease using the polymerase chain reaction. Journal of Phytopathology, 147, 599 - 604.
3. Hung, T. H., Hung, S. C, Chen. S. N., Hsu, M.
H.. & Su. H. J. (2004). Detection by PCR of Candidatus Liberibacter asiaticus, the bacterium causing citrus of huanglongbin in vector psyllids:
application to the stiidy of vector-pathogen relationships. Plantpatiiology, 53, 96 -102.
4. Jagoueix, S., Bove, J. M.. &. Garnier, M.
(1996). PCR detection of the two 'Candidatus' liberobacter species associated with greening
disease of citrus. Molecular Cellular Probes. 10. 43 - 50
5. Jagoueix, S.. Bove, J. M., & Gamier. M.
(1997). Companson of the 16S/23S Ribosomal Intergenic Regions of "Candidatus Liberobacter asiaticum" and "Candidatus Liberobacter africanum, the two species associated wnth Citiais Huanglongbing (Greening) Disease", International Journal of Systematic Bactenology, 47,224 - 227.
6. Khripach, V., Zhabinskii, V., & De Groot. A.
(2003). Twenty years of brassinosteroids: Steroidal plant hormones warrant better crops for the XXI century. Ann. Bot. 2000; 86: 441-447.
7. Knshna, P. (2003). Brassinosteroid-mediated stress responses. Journal of Plant Growth Regul; 22:
289-297.
8. Le Mai Nhdt (2014). Nghien ciiu benh vdng la Greening hai cdy cd mui a mdt sd tinh phia Bdc Vidt Nam vd de xuat bien phap phdng chdng. Ludn dn Tien si ndng nghiep. Vidn Khoa hoc Nong nghidp Viet Nam. 148 ti'ang.
9. Nguyen Minh Chon (2010). Gido binh chat didu hda sinh trudng thuc vat. Nxb Dai hpc Can Tho.
10. Nguydn Bdo Vp, Le Thanh Phong (2011).
Gido trinh cay an trai. Nxb Dai hpc Can Tho. 205 trang.
11. Nguyen Thi Minh Chdu, Nguydn Bao Ve (2005). Anh hudng cua dung dich phun la (ZnSO, + MnSOj) den trieu chiing vang la gan xanh d cam Mat va quyt Dudng cd tudi cay va muc dp benh khac nhau. Hdi thao Qudc gia nam 2005 "Cay co miii, xoai va khdm" tai Dai hpc Can Tha, td chiic ngay 1/3/2005. Nxb Nong nghiep. 416 ti'ang.
12. Rao, S. S. R.. Vardhini. B. V., Sujatha, E., &
Anuradha. S. (2002). Brassinosteroids-A new class of phytohormones- India. Current Sci., 10 (82). 1239 - 1245.
13. Schneider, H.. 1968. Anatomy of greening diseased sweet orange shoots. Phytopathology, 58:
1155-1160.
14. Whitaker, D. C, Giurcanu, M. C, Young, L J.. Gonzalez, P.. Etxeberria, E.. Roberts, P., ...
Roman. F. (2014). Starch content of citrus leaves permits diagnosis of huanglongbing in the warm season but not cool season. HortScience, 49: 757 - 762.
^"^*'^ fci^Mirnv* PWATTPJIM NONG THON - KY 1 -THANG9/2019 41
KHOA HOC CONG NGHfe
15.Takushi.T.,TToyozato. S. Kawano.S.Taba, brassinosteroids on growth, metabolite content and K. Taba, A Ooshiro, M. Xumazawa and M Tokeshi. yield oiArachishypogaea. f^jitocheniisin: A** 927-930.
2007. Scratch method for simple, rapid diagnosis of jy Wang, C. F., You, Y„ Chen, F.. Lu. X. S., citiiis huanglongbing using iodine to detect high Wang, J., & Wang, J. S. (2004). Adjusting effect of accumulation of starch in die citrus leaves. Annals of brassmohde and GA, on the orange growth. Acta the Phytopathological Society of Japan, Vol. 73, No.l Agriculturae Universitatis Jiangxiensis . 26(5): 759 - (20070225) pp. 3-8. 762.
16. Vardhini, B. V., & Rao. S. S. R.. (1998). Effect of
EFFECT OF BRASSINOLIDE CONCENTRATIONS ON THE CrTRUS GREENING, YIELD AND FRUrr QUALITY OF TJA XANH" POMELO {Citrus maxima (Burm.) Merr.) ON KE SACH
DISTRICT, SOCntANG PROVINCE
Lang Hoai Phong, Huynh Le Anh Nhi, Tran Van Hau, Tran Sy Hieu Summary
The study was conducted to determine ihe effect of Brassinolide concentration spraying on leaves on the rate and index of greening \ cllownng disease, productivity and quality of 'Da xanh' pomelo, TTie experiment was conducted on a 15-year-old "Da xanh" pomelo tree in Kc Sach distnct. Soc Trang province.
ImplementaUon period from June 2017 to june 2018. The exi)eriment was arranged in a completely randomized block form, with 5 UeaUncnls which were BR concentrations: (i) 0.05 pM; (li) 0.10 nM; and (iii) 0.15 nM. Positive control treatment with ZnSOj + MnSO, solution 0.5%. Negative control water spray, 6 repetitions, each repetition corresponds to one tree. Treatment of BR spraying is done penodically every 2 weeks when pomelo trees are perpare to leaves until the fmits are harvested (12 months). The presence of Candidatus Iibenbacter asiaticus, before and after the compIeUon of the expenment was determined by PCR using specific pnmers and Iodine-starch reaction quantifying starch content in leaves. The results showed diat spraying BR at 0.10 and 0.15 ^lM periodically twice a week for 12 months was effecUve on observe red parameters relaung to disease assessment, the presence of causal bactena, improving flowering, yield and fruil quality of 'Da xanh' grapefruit Particularly, spraying BR at 0.15 ^M resulted in a significant reduction on both rate of disease leaf on branches and disease index only after three months of frealmenl, and the lowest levels of the two parameters at the 12"' mondi afl:er treaunent (MAT). In addition.
BR 0,15 pM treatment also reduced the presence of the causal agent to an undetectable level by PCR a the 12"' MAT. reduced starch content in die leaves, increased die rale of fruiUng. yield and quality of 'Da xanh' pomelo.
Keywords.- Brassinolide. D.\.A electrophore.-is. leaf starch content, 'Da xanh'pomelo.
Ngudi phdn bi§n: TS. Hd Minh Thanh Ngdy nhdn bdi: 15/4/2019 Ngdy thdng qua phdn bi$n: 16/5/2019 Ngdy duyet dang: 23/5/2019
N O N G NGHIEP VA PHAT TRIEN NONG THON - KY 1 - THANG 9/2019
